What Is the Mean Free Path for the Molecules in an Ideal

What is the mean free path for the molecules in an ideal gas when the pressure is 100 kPa and the temperature is 300 K given that the collision cross-section for the molecules of that gas is 2.0 × 10^-20 m²? The Boltzmann constant is 1.38 × 10^-23 J/K,Avogadro's number is 6.02 × 10²³ molecules/mole,and the ideal gas constant is R = 8.314 J/mol ∙ K =
0.0821 L ∙ atm/mol ∙ K.

A) 1.1 × 10^-6 m
B) 2.1 × 10^-6 m
C) 1.7 × 10^-6 m
D) 5.3 × 10^-6 m
E) 1.5 × 10^-6 m